In grid-connected DC-AC converters (hereinafter“inverters”) an output filter can be used to improve power quality. The output filter can be an LCL filter. It has been known that hardware size and costs of the inductors on the LCL filter can possibly be reduced by operating the inductors in the nonlinear region of their B-H curve, as this enables smaller inductors. However, various technical problems have obstructed their use in a range of applications. One such technical problem can be stability in the LCL filters. Another technical problem, or set of technical problems, can result from inherent uncertainty of the non-linear inductor's instant inductance value. These may prevent or obstruct use of non-linear LCL filter inductors for some applications. One such application can be grid-connected inverters using, for feedback control, a measurement of current through one LCL inductor, and an estimate of current through another of the inductors. This can enable reduction in the number of current sensors and, hence, costs. However, the estimation of inductor current requires prior knowledge of the inductance values. Use of non-linear inductors, which have inherent variance in their inductance value, can remove the capability the estimation. This can necessitate additional current sensors, negating savings from reduced inductor size.
Accordingly, there is a need in the grid connected inverter field for a technical solution to reduce inductor costs without incurring other hardware costs or complexities.